Ultrasound-modulated optical tomography is a noninvasive imaging technique for biomedical diagnosis. With this technique, an imaging system takes advantage of focused ultrasonic field to mark the photon trajectories in a biological sample by modulating the optical path in the focal zone. The tagged photon reflects the local optical and mechanical properties in the ultrasonic focal zone and permits tomographic imaging of biological tissues by scanning. Based on the high-sensitivity detection technique, we have developed a reflective and coaxial configuration, which was more convenient and hopeful to produce an easy-controlling setup for practical application. In addition, this configuration can bring a new method to improve the spatial resolution of the tomographic plane paralle to the ultrasonic axis in the traditional configuration. Optical tomographys of the biological tissue were successfully obtained experimentally.
Chemiluminescence (CL) is a highly sensitive detection method with broad biological applications. In this work, a CL detection system is developed and applied in detection the CL from human lymphocyte induced with Co-60 irradiation, for the first time. The radiation damage of lymphocyte was detected by cell counting and MTT method for various irradiation doses. The results show a good correlation between the CL intensity and the radiation-induced damage of lymphocyte. Cell activity increased gradually with the increase of radiate dose, when the dose was under 3Gy. When the radiate dose was above 3Gy, the results were contrary. The cell counting results corresponded well with the MTT method. The CL detection method, thus, may provide an alternative way in evaluation of radiation damage.
In this paper, a novel method for photoacoustic (PA) waves to imaging is proposed. A focused probe ultrasonic beam passes through a specimen and tags the position of the interested PA signal. Reconstruction of the original PA signal in situ is accomplished by demodulating the probe-beam. The method provides new measurement system with to improve signal-to-noise ratio and to take out more original messages. Applied the proper impulse of the detector and filter-back-project algorithm, a 2D PA tomograph was obtained.
Ultrasound-modulated optical tomography affords a very promising noninvasive imaging method for biomedical diagnosis. In this technology ultrasonic beams are focused into a scattering medium to provided accurate localization and simultaneously modulate light inside the medium. The detected ultrasound-tagging photons will bring the information of the characteristics of the medium. Based on the high-sensitivity detection technique, we develop a unique reflective configuration that the ultrasound and light are kept coaxial, which is more convenient and practical than other configurations. A completely absorbing object imbedded in a tissue is imaged using the corresponding experimental setup designed by us which is based on the configuration.
Photoacoustic (PA) technique is a very important and promising biomedical diagnosis and imaging method, which can afford abundant information to analyze the pathological part of the tissue and image it. This paper proposes a new method to detect the PA wave. A focused probe ultrasonic beam was used to tag the position of PA signal and simultaneously overlapped with the PA signal, which in fact is carried out by the probe ultrasound. The overlapped signal is received by the transducer and will be further processed such as amplification and digitization. At last a compute analyzes and processes the digitized signal and the original PA signal can be restored by Fourier filtering. Furthermore, the noise of the measurement system and background could be reduced after filtering. On the basis of this method, we designed a novel setup to detect breast cancer tumor and the performance of this setup was evaluated in breast tissue-like phantom. The experiment results demonstrate the practicability of this technique.